Future Trends and Challenges for Mobile and Convergent Networks

Some traffic characteristics like real-time, location-based, and community-inspired, as well as the exponential increase on the data traffic in mobile networks, are challenging the academia and standardization communities to manage these networks in completely novel and intelligent ways, otherwise, current network infrastructures can not offer a connection service with an acceptable quality for both emergent traffic demand and application requisites. In this way, a very relevant research problem that needs to be addressed is how a heterogeneous wireless access infrastructure should be controlled to offer a network access with a proper level of quality for diverse flows ending at multi-mode devices in mobile scenarios. The current chapter reviews recent research and standardization work developed under the most used wireless access technologies and mobile access proposals. It comprehensively outlines the impact on the deployment of those technologies in future networking environments, not only on the network performance but also in how the most important requirements of several relevant players, such as, content providers, network operators, and users/terminals can be addressed. Finally, the chapter concludes referring the most notable aspects in how the environment of future networks are expected to evolve like technology convergence, service convergence, terminal convergence, market convergence, environmental awareness, energy-efficiency, self-organized and intelligent infrastructure, as well as the most important functional requisites to be addressed through that infrastructure such as flow mobility, data offloading, load balancing and vertical multihoming.Comment: In book 4G & Beyond: The Convergence of Networks, Devices and Services, Nova Science Publishers, 201

An Overview on IEEE 802.11bf: WLAN Sensing

With recent advancements, the wireless local area network (WLAN) or wireless fidelity (Wi-Fi) technology has been successfully utilized to realize sensing functionalities such as detection, localization, and recognition. However, the WLANs standards are developed mainly for the purpose of communication, and thus may not be able to meet the stringent requirements for emerging sensing applications. To resolve this issue, a new Task Group (TG), namely IEEE 802.11bf, has been established by the IEEE 802.11 working group, with the objective of creating a new amendment to the WLAN standard to meet advanced sensing requirements while minimizing the effect on communications. This paper provides a comprehensive overview on the up-to-date efforts in the IEEE 802.11bf TG. First, we introduce the definition of the 802.11bf amendment and its formation and standardization timeline. Next, we discuss the WLAN sensing use cases with the corresponding key performance indicator (KPI) requirements. After reviewing previous WLAN sensing research based on communication-oriented WLAN standards, we identify their limitations and underscore the practical need for the new sensing-oriented amendment in 802.11bf. Furthermore, we discuss the WLAN sensing framework and procedure used for measurement acquisition, by considering both sensing at sub-7GHz and directional multi-gigabit (DMG) sensing at 60 GHz, respectively, and address their shared features, similarities, and differences. In addition, we present various candidate technical features for IEEE 802.11bf, including waveform/sequence design, feedback types, as well as quantization and compression techniques. We also describe the methodologies and the channel modeling used by the IEEE 802.11bf TG for evaluation. Finally, we discuss the challenges and future research directions to motivate more research endeavors towards this field in details.Comment: 31 pages, 25 figures, this is a significant updated version of arXiv:2207.0485

Cooperative Communications in Ad Hoc Networks

Les techniques de communication coopératives ont été proposées pour améliorer la qualité des signaux reçus par les terminaux sans fil grâce au principe de diversité spatiale. Cette propriété est obtenue par une duplication du signal, envoyé par l’émetteur au niveau d’un terminal relais situé entre l’émetteur et le récepteur. Les travaux de recherche menés en communications coopératives concernent deux domaines principaux: certains traitent la transmission physique alors que d’autres sont étudient l’interaction de la couche physique avec les couches protocolaires supérieures, en particulier les niveaux MAC (Medium Access Control) et réseau. Si ces domaines de recherche sont généralement séparés, des études conjointes s’avèrent nécessaires pour obtenir des systèmes coopératifs implantables. C’est dans ce contexte que se situent les travaux de la thèse avec, comme cadre applicatif, les réseaux ad hoc. En premier lieu, dans la mesure où il n’existe pas de modèle complet de système coopératif, un cadre de modélisation original est proposé pour représenter le fonctionnement d’un système coopératif, sa mise en place et son fonctionnement. Une caractéristique du modèle est de faire abstraction des couches protocolaires. Cette façon de procéder permet d’analyser de façon similaire différentes solutions proposées dans la littérature. De plus, ce modèle facilite la conception de solutions coopératives, en particulier la conception du processus de mise en place du système de coopération qui initialise les rôles de relais, destinataire et source en fonctionnement coopératif. Le modèle de système coopératif est utilisé pour la conception d’une solution de transmission coopérative adaptative où le relais agit en tant que proxy entre la source et le destinataire. L’intérêt de notre proposition, ProxyCoop, par rapport à d’autres propositions, est d’être compatible avec le protocole IEEE 802.11 que ce soit dans son mode de base ou dans son mode optionnel. Pour chaque trame, le mode de transmission à la source est dynamiquement défini soit en mode proxy coopératif soit en mode non coopératif, et ce en fonction de la réception ou la non réception d’un acquittement du destinataire. Les résultats de simulation montrent, sous certaines conditions, une amélioration des performances en termes de nombre de trames effectivement reçues. Le nombre de retransmissions dues à des trames reçues erronées est diminué, et les transmissions en mode multi saut, coûteuses en temps et en bande passante sont également diminuées. Les conditions favorables à la coopération sont dépendantes de la qualité et de l’accessibilité du canal. Une méthode pour la mise en place du système coopératif est également proposée. Elle repose sur l’utilisation d’un protocole standard de routage pour réseaux ad hoc, AODV. Les évaluations de performances indiquent que la mise en place du système de coopération coûte peu en termes de bande passante, les performances du système (mise en place et fonctionnement) sont supérieures à celles d’un système non-coopératif, pour des conditions données. Finalement, l’application de la solution proposée à un réseau ad hoc spécifique, un réseau maillé (mesh) conforme au standard IEEE 802.11s illustre où et comment déployer la solution proposée. ABSTRACT : Cooperative communication techniques have been proposed in order to improve the quality of the received signals at the receivers by using the diversity added by duplication of signals sent by relay terminals situated between each transmission pair. Researches related to cooperative communication can be categorized into two fields; Cooperative transmissions and Cooperative setup. The first research field concerns with cooperative transmission techniques in the physical layer while the second research field concerns with issues on inter-layer interaction between cooperative transmissions in the physical layer to protocols in the upper layers (especially the MAC layer and the network layer). These research topics have been separately concerned but, for implementations, they have to work together. Since there is not any existing common frame work to describe entire functions in cooperative communication, we proposed an original framework of cooperative network at the system level called “Cooperative Network Model”. The model does not reflect the protocol layering; thus, we can generalize the cooperation process and obtain an analysis that is available for many solutions. For validity, the proposed model can clearly illustrate and systematically describe existing cooperative setup protocols. In addition, the proposed cooperative network model facilitates us to find and to solve problems in cooperative designs; especially in cooperative setup, which is in charge on the initiation of the terminal’s role (i.e., a source, a relay, and a destination terminal). Thus, we believe that this model can facilitate the design and updating of existing and future propositions in this domain. The cooperative network protocol is used to design an adaptive cooperative transmission called Proxy Cooperative Transmission. In contrast to other adaptive cooperative transmission techniques, our proposition is compatible to both of the basic access mode and the optional access mode of IEEE 802.11 Medium Access Control (MAC) protocol. The transmission mode for each data frame is adaptively switched between a proxy cooperative mode and a non-cooperative mode based on the absence of acknowledge (ACK) frame. Simulation results show that transmission performance is improved by decreasing the number of re-transmissions due to frame errors; thus, chances of multi-hop mode transitions that are costly in time and bandwidth are alleviated. Then, in order to fulfill ProxyCoop communications in part of cooperative setup, we propose a cooperative setup method called “Proxy Cooperative Setup”. The proposition is based on a routing standard protocol for ad hoc networks, AODV, so that it could be easily deployed. The impacts of ProxyCoopSetup when it works with ProxyCoop transmissions have been studied. From simulation results, it shows that ProxyCoop transmissions with ProxyCoopSetup has similar performance to the ProxyCoop transmissions without ProxyCoopSetup. Finally, when the implementation of the proxy cooperative communication and how it can be integrated on existing networks have been considered, it is shown that the design of proxy cooperative communication is also valuable for the 802.11s WLAN Mesh Network environments

Channel Based Relay Attack Detection Protocol

A relay attack is a potentially devastating form of a man-in-the-middle attack, that can circumvent any challenge-response authentication protocol. A relay attack also has no known cryptographic solution. This thesis proposes the usage of reciprocal channel state information in a wireless system to detect the presence of a relay attack. Through the usage of an open source channel state information tool, a challenge-response authentication Channel Based Relay Attack Detection Protocol is designed and implemented using IEEE 802.11n (WiFi) in detail. The proposed protocol adapts ideas from solutions to other problems, to create a novel solution to the relay attack problem. Preliminary results are done to show the practicality of using channel state information for randomness extraction. As well, two novel attacks are proposed that could be used to defeat the protocol and other similar protocols. To handle these attacks, two modifications are given that only work with the Channel Based Relay Attack Detection Protocol

Radio Communications

In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks

Robust, Resilient Networked Communication in Challenged Environments

In challenged environments, digital communication infrastructure may be difficult or even impossible to access. This is especially true in rural and developing regions, as well as in any region during a time of political or environmental crisis. We advance the state of the art in wireless networking and security to design networks and applications that rapidly assess changing networking conditions to restore communication and provide local situational awareness. This dissertation examines new systems for responding to current and emerging needs for wireless networks. This work looks across the wireless ecosystem of widely deployed standards. We develop new tools to improve network assessment and to provide robust and reliable network communication. By incorporating new technological breakthroughs, such as the wide commercial success of Unmanned Aircraft Systems (UAS), we introduce novel methods and systems for existing wireless standards for these challenged networks. We assess how existing technologies and standards function in difficult environments: lacking end-end Internet connectivity, experiencing overload or other resource constraints, and operating in three dimensional space. Through this lens, we demonstrate how to optimize networks to serve marginalized communities outside of first world urban cities and make our networks resilient to natural and political crisis that threaten communication

Energy Efficiency in Communications and Networks

The topic of "Energy Efficiency in Communications and Networks" attracts growing attention due to economical and environmental reasons. The amount of power consumed by information and communication technologies (ICT) is rapidly increasing, as well as the energy bill of service providers. According to a number of studies, ICT alone is responsible for a percentage which varies from 2% to 10% of the world power consumption. Thus, driving rising cost and sustainability concerns about the energy footprint of the IT infrastructure. Energy-efficiency is an aspect that until recently was only considered for battery driven devices. Today we see energy-efficiency becoming a pervasive issue that will need to be considered in all technology areas from device technology to systems management. This book is seeking to provide a compilation of novel research contributions on hardware design, architectures, protocols and algorithms that will improve the energy efficiency of communication devices and networks and lead to a more energy proportional technology infrastructure

Comunicações veiculares híbridas

Vehicle Communications is a promising research field, with a great potential for the development of new applications capable of improving road safety, traffic efficiency, as well as passenger comfort and infotainment. Vehicle communication technologies can be short-range, such as ETSI ITS-G5 or the 5G PC5 sidelink channel, or long-range, using the cellular network (LTE or 5G). However, none of the technologies alone can support the expected variety of applications for a large number of vehicles, nor all the temporal and spatial requirements of connected and autonomous vehicles. Thus, it is proposed the collaborative or hybrid use of short-range communications, with lower latency, and of long-range technologies, potentially with higher latency, but integrating aggregated data of wider geographic scope. In this context, this work presents a hybrid vehicle communications model, capable of providing connectivity through two Radio Access Technologies (RAT), namely, ETSI ITS-G5 and LTE, to increase the probability of message delivery and, consequently, achieving a more robust, efficient and secure vehicle communication system. The implementation of short-range communication channels is done using Raw Packet Sockets, while the cellular connection is established using the Advanced Messaging Queuing Protocol (AMQP) protocol. The main contribution of this dissertation focuses on the design, implementation and evaluation of a Hybrid Routing Sublayer, capable of isolating messages that are formed/decoded from transmission/reception processes. This layer is, therefore, capable of managing traffic coming/destined to the application layer of intelligent transport systems (ITS), adapting and passing ITS messages between the highest layers of the protocol stack and the available radio access technologies. The Hybrid Routing Sublayer also reduces the financial costs due to the use of cellular communications and increases the efficiency of the use of the available electromagnetic spectrum, by introducing a cellular link controller using a Beacon Detector, which takes informed decisions related to the need to connect to a cellular network, according to different scenarios. The experimental results prove that hybrid vehicular communications meet the requirements of cooperative intelligent transport systems, by taking advantage of the benefits of both communication technologies. When evaluated independently, the ITS-G5 technology has obvious advantages in terms of latency over the LTE technology, while the LTE technology performs better than ITS-G5, in terms of throughput and reliability.As Comunicações Veiculares são um campo de pesquisa promissor, com um grande potencial de desenvolvimento de novas aplicações capazes de melhorar a segurança nas estradas, a eficiência do tráfego, bem com o conforto e entretenimento dos passageiros. As tecnologias de comunicação veícular podem ser de curto alcance, como por exemplo ETSI ITS-G5 ou o canal PC5 do 5G, ou de longo alcance, recorrendo à rede celular (LTE ou 5G). No entanto, nenhuma das tecnologias por si só, consegue suportar a variedade expectável de aplicações para um número de veículos elevado nem tampouco todos os requisitos temporais e espaciais dos veículos conectados e autónomos. Assim, é proposto o uso colaborativo ou híbrido de comunicações de curto alcance, com latências menores, e de tecnologias de longo alcance, potencialmente com maiores latências, mas integrando dados agregados de maior abrangência geográfica. Neste contexto, este trabalho apresenta um modelo de comunicações veiculares híbrido, capaz de fornecer conectividade por meio de duas Tecnologias de Acesso por Rádio (RAT), a saber, ETSI ITS-G5 e LTE, para aumentar a probabilidade de entrega de mensagens e, consequentemente, alcançar um sistema de comunicação veicular mais robusto, eficiente e seguro. A implementação de canais de comunicação de curto alcance é feita usando Raw Packet Sockets, enquanto que a ligação celular é estabelecida usando o protocolo Advanced Messaging Queuing Protocol (AMQP). A contribuição principal desta dissertação foca-se no projeto, implementação e avaliação de uma sub camada hibrída de encaminhamento, capaz de isolar mensagens que se formam/descodificam a partir de processos de transmissão/receção. Esta camadada é, portanto, capaz de gerir o tráfego proveniente/destinado à camada de aplicação de sistemas inteligentes de transportes (ITS) adaptando e passando mensagens ITS entre as camadas mais altas da pilha protocolar e as tecnologias de acesso rádio disponíveis. A sub camada hibrída de encaminhamento também potencia uma redução dos custos financeiros devidos ao uso de comunicações celulares e aumenta a eficiência do uso do espectro electromagnético disponível, ao introduzir um múdulo controlador da ligação celular, utilizando um Beacon Detector, que toma decisões informadas relacionadas com a necessidade de uma conexão a uma rede celular, de acordo com diferentes cenários. Os resultados experimentais comprovam que as comunicações veículares híbridas cumprem os requisitos dos sistemas cooperativos de transporte inteligentes, ao tirarem partido das vantagens de ambas tecnologias de comunicação. Quando avaliadas de forma independente, constata-se que que a tecnologia ITS-G5 tem vantagens evidentes em termos de latência sobre a tecnologia LTE, enquanto que a tecnologia LTE tem melhor desempenho que a LTE, ai nível de débito e fiabilidade.Mestrado em Engenharia Eletrónica e Telecomunicaçõe